The purpose of this new project is to study Aleutian disease, a severe fatal immune complex disease of mink associated with a persistent viral infection. The project is a concerted effort and will focus techniques of immunology and virology on Aleutian disease. The current objectives are to characterize Aleutian disease virus (ADV) by standard virological methodology and to determine what role viral components have in the genesis of the immune complexes. Additional objectives are to study the immunoglobulin class-specific antibody response to ADV and to ascertain if severe immune complex disease correlates with a specific immunoglobulin class of antiviral antibodies.